Timer



Aug. 8, 1961 D. M. STRATHEARN EIAL 2,995,143

7 TIMER Filed March 16, '1959 e Sheets-Sheet 1 INVENTORS DONALDM.5TRATHEARN F\ 6. 3 IAME-s W. THORNBERY ATTORNY Aug. 8, 1961 D. M.STRATHEARN ET AL 2,995,143

TIMER Filed March 16, 1959 6 Sheets-Sheet 2 sc, 51 sa sAse,

78 INVENTORS DONALD M. STRATHEAMI James W. Taoauseav .11.. I! II I BYFla- 2b Aug. 1961 D. M. STRATHEARN ET AL 2,995,143

TIMER Filed March 16, 1959 6 Sheets-Sheet 3 OJ :0 tum-(oar m3 9 2 l -%\kfl l E 3 & Isl f 2 o m .J l m m o l 2 O \D 2 TJ 3 5 I on O O a. I 3 Fl 0F 5 AA 1- V fi 2 3 m E; L \m cc 3 O I E #1 3 JVASII J INVENTORS Dem/.0M. STRATHEARN JAMES M. THORNBERY ATTORNEY g- 1961 0. M. STRATHEARN ET AL2,995,143

TIMER 6 Sheets-Sheet 5 Filed March 16, 1959 FILL PSkl FILL ms com) TIMI!LINE PUMP NE I must LITE WASHLITE E0 ZEW 2:5 2 2.5.0 .55 2E- T m T R O Bm G E R N U of. wa v M E Va N NT R I M o .T "U M A a a M..- NM 0A DJAug. 8, 1961 D. M. STRATHEARN ETAL 2,995,143

TIMER Filed March 16. 1959 6 Sheets-Sheet 6 GOLD COLD WASH'N'WEAR DRIPDRY BLANKET INVENTORS DONALD ML'STRAYMIAII. JAMES M. Tuoluvlnv @BL/JKM/A'rfanu EV Fm. B

United States Patent O Filed Mar. 16, 1959, Ser. No. 799,780 Claims.(Cl. 137-387) This invention relates to sequence timers and particularlyto such timers affording a plurality of programs.

Sequence timers operating on rotation of a drum can be visualized ashaving 360 rotation available for containing the desired programs. Eachprogram requires a portion of the 360 available and it will be obviousthat the :greater the number of programs provided, the less space isavailable between programs. This space is utilized as a starting pointand as the space is reduced the manual selection of the desired spacebecomes increasingly difficult until it becomes unreasonably diflicultwithout mechanical or electro-mechanical assistance. To further simplifythe process, it has become desirable to automatically position the timerat the desired starting point electro-mechanically in response toselection of a desired program by the operator actuating one (or more)switches which energize a positioning motor to drive the timer at highspeed to the starting point. This has been done in co-pending Thornberyet al. application Serial Number 799,781, filed March 16, 1959 (assignedto applicants assignee), with an interval timer combined with a seekingcircuit and a separate high speed drive for the timer.

An object of this invention is to simplify the structure of Thornbery etal. and particularly to simplify the high speed drive. This has beendone by having the high speed positioning motor drive the timer cam drumthrough the slow speed drive mechanism as compared to the Thombery etal. arrangement utilizing two separate drives.

In order to provide a step (in the stepping drive) adequate to insuregood switching on the cam drum periphery while retaining a workable sizeand torque requirement, it is generally found that a 6 or 7.2 step isdesirable. With this limitation on the interval and with commercialrequirements for more programs in the available intervals it becomesincreasingly desirable to find some way to increase the functions whichcan be provided for by the timer. Reduction of the interval leads toswitching problems and does not appear to be an attractive solution.Furthermore, often an entire interval must be devoted to an operationnot requiring the entire interval (in time) for completion.

Another object of this invention is to provide means for increasing thefunctions possible within an interval of a timer sequence. This has beenaccomplished by what is called sub-interval switching which in a senseis like a separate timer having a switching sequence which may beselected by the main timer during any desired interval to therebyprovide a sub-sequence within a given interval of the sequence providedby the main timer. This makes possible the maximum utilization of aninterval. Thus, while the timer remains at an interval for one minute,for example, the function may take less time and the remainder of theinterval is, in effect, wasted. However, with sub-interval switching thefirst portion of an interval may provide for (in a washing machine)rinse the remainder may be drain." This may be accomplished in oneinterval. Other possibilities are pointed out hereinafter and manyothers will be apparent to those skilled in the art. Sub-intervalswitching has the eifect of increasing the number of intervals withouthaving to reduce the increment. Therefore, the sub-interval switchingmakes "ice possible more programs in a timer of given size and interval.

In connection with the high speed drive of the timer to its startingpoint, it is necessary to preclude advancing more than one step at atime.

It is another object of this invention, therefore, to provide a drivewhich is useable at high speed and prevents over-stepping. This has beenaccomplished through use of a verge drive mechanism resulting in a drivesuitable for both high and low speed operation. When combined with ananti-reverse ratchet, a further advantage is realized in that the timercan not be advanced or reversed manually by actuation of the timershaft. The latter feature allows an indicator to be mounted on theshaft, if desired, without fear that the operator will attempt to setthe timer manually.

Another object of the invention is to provide a seeking circuitincorporating novel features of program selection whereby one selectionswitch can sequentially select two programs which should follow eachother. Another feature of the circuit is the automatic selection of anoff position in the event the selection switches are improperlyactuated.

Other objects and advantages will be pointed out in or be apparent fromthe specification and claims, as will obvious modifications of thesingle embodiment shown in the drawings, in which:

FIGURE 1 is a top plan view of the timer;

FIGURE 2 is a front elevation, partly in section;

FIGURE 3 is a view of the printed circuit board utilized in connectionwith the searching circuit;

FIGURE 4 is a view of the drive mechanism;

FIGURE 5 is another view taken to show the general switching arrangementof both the main timer and of the sub-interval switching;

FIGURE 6 is a view through the shaded pole motor and showing the switchoperated by the motor when energized;

FIGURE 7 is similar to FIGURE 6 but shows the motor in its energizedposition;

FIGURE 8 is a schematic representation of the searching circuit andmechanism;

FIGURE 9 is a wiring diagram for both the searching circuit and theentire washing machine and timer circuit;

FIGURE 10 is a schematic representation of the subinterval switchingsequence; and

FIGURES 11, A and B show the program achieved by the presentarrangement.

The structure shown is built around a basic interval timer differentfrom the usual timer only in that it has a great number of programsavailable within the 360 of rotation. Thus, the timer is provided with apair of terminal boards 20, 22 which carry the program switchesgenerally designated 24. The terminal boards are carried between endplates 26, 28 and the switches are provided with cam followers which acton cams 30 carried on arbor '32. As will appear hereinafter, the endplate 28 has a printed circuit thereon as indicated in FIGURE 3. Thearbor 32 is journalled in the end plates for rotation and carries adrive ratchet 34 which is adapted to receive the impulses from the timermotor 36 or from the shaded pole motor 38. It will be noted that endplate 26 carries pawl 39 loaded by spring 42 into engagement with theteeth on the drive ratchet 34 to prevent reverse rotation of the timerarbor. Of course, since the timer is not manually actuated, there is nodanger of manual reverse rotation but there is some possibility of thedrive mechanism to the ratchet 34 tending to drag the arbor back and thepawl 39 prevents such action.

With the exception of the printed circuit board, the mechanism describedthus far is quite customary. The timer motor drives the ratchet througha novel drive mechanism. The motor 36 includes, as is customary, a gearreduction in the larger part of the motor housing and also includes anoverrunning clutch (not shown) which may be of any desired construction,to turn the motor shaft 40 in a counter-clockwise direction. The shaftcarries a molded disc including the cam 41. The purpose of this cam issimilar to that of the prior art in that it gradually builds up energyin the drive mechanism and at its drop permits a rapid delivery of thisenergy through the drive to the arbor. Thus a lowtorque motor can beused to deliver a high torque impulse. The cam drop is preferably of theslow drop type described more fully in co-pending application SerialNumber 520,946, now Patent Number 2,934,618. Lever or link 44 is pivotedon post 46 and is biased by spring 48 hearing against the frame andwound around the post to act against the vertical portion of the link(FIGURE 2) to force the follower portion 50 into contact with theperiphery of the cam 41. The left end (FIGURE 4) of lever 44 carriesverge 52 pivoted on pin 54. The toe or leading tooth 56 of the verge isbiased into constant contact with ratchet 34- by spring 58. The heel ortrailing tooth 60 will lift out of the teeth after each impulse. As thecam 41 rotates (usually at 1 rpm.) the lever 44 will rock in a clockwisedirection slowly and the toe 56 of verge 52 will ride up the slopingportion of the next rearward ratchet tooth and shortly before theimpulse is given to the lever the toe will drop into the next notch onthe ratchet ready for delivery of the power stroke or impulse. When thefollower reaches the drop portion of the cam 41, the lever will rapidlyrock in a counter-clockwise direction about its pivot 46 and drive thetoe 56 against the ratchet. Simultaneously with this action, the verge52 will rock about its pivot in a clockwise direction to jam the heel 60into a corresponding ratchet tooth as may be seen in FIGURE 4. With boththe leading and trailing teeth engaged, it is impossible for the ratchetto rotate more than one step as imparted by the link and thus, thetrailing tooth serves to prevent overstepping. This is of greatimportance in the present drive where the impulses are given rapidly andfrequently during the high speed drive to be described hereinafter.Overstepping cannot, of course, be tolerated in this situation and thepresent drive prevents any overstepping and limits the indexing of thearbor to one step per impulse from the drive.

As mentioned above, the cam 41 is carried on a disc 62, the periphery ofwhich is in the form of a gear engaging pinion 64 which is adapted to bedriven by the shaded pole motor 38. When the shaded pole motor isde-energized as shown in FIGURE 6, the pinion is not connected to themotor since spring 66 biases the rotor 68 upwardly to move the clutchhalf 70 out of engagement with the clutch half 72 connected to the gear64. When the motor is energized, as shown in FIGURE 7, the rotor ispulled between the shaded poles 74 with a solenoid action and the upperclutch half 70 is pulled down into engagement with the lower clutch half72 and the rotor of the shaded pole motor is connected to gear 64 to, inturn, transmit power to gear disc 62. This will, of course, rotate thecam 41 and deliver impulses to the ratchet on the arbor as before exceptthat the impulses will be delivered quite rapidly (generally in theneighborhood of six per second). When the shaded pole motor isde-energized, the clutch spring 66 will immediately move the rotor backto the position shown in FIGURE 6 in which the rotor is disengaged fromthe pinion 64. Thus, the inertia of the rotor is immediately removedfrom the drive when the shaded pole motor is de-energized and, hence,the inertia of the motor will not tend to over drive the timer past thedesired point.

A further feature to be noted in FIGURES 6 and 7 is that the lower endof the rotor shaft 76 is provided with a switch actuating boss 78bearing on the actuating end of the switch blade 80 of a ratherconventional snap acting switch. In the position shown in FIGURE 6, theswitch .4 contact 82 is acting on the lower stationary contact 84. Whenthe shaded pole motor is actuated as in FIGURE 7, the switch blade ismoved down and throws the switch overcenter so the contact 82 nowcontacts the upper fixed contact 86. The purpose of this transfer switchwill be pointed out more fully hereinafter in connection with the wiringdiagram.

In FIGURE 4 it will be noted that there is shown in dotted lines on disc62, a number of face cams which are on the underside of the disc and maybe seen in part in FIGURE 2. These cams actuate a group of switches onlyone of which need be considered at this moment. Thus, the inside cam 88is designed to actuate follower 90 (FIGURE 5 which, in turn, actuatesthe searching switch SS to open the switch SS once for each revolutionof the disc.

Returning now to FIGURE 3 which illustrates the printed circuit found onthe end panel 28, it should be noted that the brush wiper 92 carried bythe arbor for rotation therewith (FIGURES 2 and 5) wipes three circularpaths on the printed circuit. Thus, while the middle arm 94 runs on theinner circular track while the middle wiper arm 96 runs on the outerportion of the nearly circular path 98 so as to overlie the cutoutportions of the track. The outer wiper arm 100 wipes on the inner end ofthe various fragments which generally line up with the notches in themiddle track 98. By a switching arrangement which will be more fullyexplained in connection with FIGURES 8 and 9 the slender portionsopposite the notches are, in effect, placed into the notch (electricallyspeaking) when the corresponding switch is closed and, hence, the brushrunning on the inner track can complete the circuit across the inner andmiddle track. If the switch to one of the finger-like circuit portionsprinted opposite a notch in the middle track is open, there can be nocompleted circuit and this will constitute an open circuit which thesystem is designed to seek.

This seeking circuit is readily understood in connection with FIGURE 8which shows the essential portions of the circuit. This figure,incidentally, shows the circuit relationship of the printed circuit andthe brush 92 rather clearly and demonstrates that the brush merely actsas a jumper in the circuit arrangement. The small circular segments onthe periphery of the representation of the printed circuit correspond tothe fingerlike projections opposite the notches in FIGURE 3. Due tospace, they cannot actually be placed as in FIGURE 8 and, hence, it isnecessary to have the brush provided with two wipers. The printedcircuit here is shown with four possible stopping points which arereferred to as M, N, O and P which are regulated by normally closedswitches as SM, SN, SO, and SP. These switches constitute the cycleselection switches. There is also a normally open momentary switch 102and the cycle selection switches are so designed that actuation of oneof these switches will also actuate the momentary switch 102. Whenswitch SM, for example, is actuated, the momentary switch will be closedand the switch SM will be opened. Closure of the momentary switch willenergize the shaded pole motor through the printed circuit and thebrush. This circuit is as follows: L1 to the lead 104 through the motorwinding 106 to junction 108 and from there through lead 110 to theprinted circuit board, through the wiper, to lead 112 and line 114 tothe momentary switch 102 and from thence to line 116 to contact 84 onthe motor switch 82 to line L2. This energizes the shaded pole motor andthe solenoid action of the rotor throws the switch 82 to contact 86 toestablish a holding circuit shunting the momentary switch and breakingthe circuit to the timer motor. At this time the shaded pole motordrives the timer at high speed to advance the wiper 92 around theprinted circuit. The advance will, of course, be step by step. Aftereach step the cam 88 allows the search switch SS to open. The searchingswitch SS is normally closed and in parallel with the printed circuitswitches. If the circuit through printed circuit is complete when thesearching switch opens the shaded pole motor will continue to advancethe timer at the rate of about six impulses per second. When the brushon the printed circuit reaches the contact segment M which is in serieswith the open cycle selection switch SM, opening the searching switchwill cause the shaded pole motor to be deenergized since the circuitthrough the motor coil 106 is broken. Immediately upon de-energizationof the shaded pole motor, spring 66 returns the rotor to the position inwhich it disengages the drive and also restores the rotor switch 82 toits normal position. In this position the timer will now be energized byreason of the fact cams driven by the timer have caused closure of thecircuit including the timer motor. This will appear more fully inconnection with FIGURES 9 and 11.

The simplified diagram of FIGURE 8 should make the operation of thesearching circuit quite clear. It should be noted that due to the factthat the searching switch SS is normally closed and is closed during theadvance of the brush, the printed circuit is, during the impulse,shunted by the searching switch. Between each impulse imparted to thetimer and its brush 92, the searching switch opens and, hence, thetesting of the circuit condition is, in effect, accomplished at thesearching switch rather than at the brush and thus avoids switching onthe printed circuit board which could conceivably have adverse affects.It should be noted, however, that as further experience is gained bothwith respect to printed circuit boards and with respect to thecapacities of a timer arrangement of this type, it appears more and morelikely that the searching switch can be eliminated if desired.

With the understanding of the searching circuit gained from theconsideration of FIGURE 8, the complete wiring diagram of the timer, thesearching circuit and the washing machine can now be considered, noting,however, that the circuit to be described now is merely representativeof one type of circuit and the present invention can be applied to manytypes of control circuits. Furthermore, it should be noted that in thesystem shown here the searching arrangement seeks an open circuit. Thesystem can readily be modified to seek a closed circuit when desired.Such a circuit is shown in the co-pending application of Thornbery eta1. Serial Number 799,781.

Turning now to FIGURE 9 and particularly to the upper portion thereof,the printed circuit is here represented by the dark strip over which thebrush 92 travels in the direction indicated by the arrow labeledrotation. Along the right-hand of the side of the wider of the twoprinted circuit strips, there is indicated the various starting pointswhich may be selected by operating one of the cycle selection switches.These switches bear the legend S1, S3 etc. with the S standing for cycleselection switch and the nuumeral 1 indicating the starting point atinterval number 1, for example. It will be noted that there is shown aswitch S68 and this indicates the same switch may be actuated toposition the brush and, hence, the timer to start at either interval 6or 8 and the purposes underlying this will be explained more fullyhereinafter. It will be noted that this wiring diagram illustrates thesearching switch SS and the shaded pole motor switch 82, the latterbeing shown in two locations in order to indicate its functionscompletely. The momentary switch 102 is also shown. With the showing ofFIG- URE 8 in mind, it will be easy to determine the manner ofoperation. For example, actuation of one of the normally closed cycleselection switches will, as mentioned above, also actuate the momentaryswitch 102. Since the timer is designed to stop at the end of a cycle orprogram in an o position with the brush bridging the printed circuit soas to result in closing the circuit at this point, this will result incurrent flow to the shaded pole motor from line L1 through the momentaryswitch to the common line 118 and from thence to line 120 and theprinted circuit strip 122 through the brush to printed circuit strip 124and from there through the motor 38 to line L2. This, of course,energizes the motor and changes the position of the shaded pole motorswitch 82. Thus, the shaded pole motor switch in line L1 will open tode-energize the entire washing machine circuit, while the shaded polemotor switch also closes the circuit from line L1 to line 118 to shuntthe momentary switch and establish a holding circuit. Now then, theshaded pole motor will rapidly advance the timer and its brush throughthe sequential intervals searching for the open circuit. After eachimpulse to advance the timer, the searching switch SS will open to allowthe circuit condition to be tested. For example, if the selection switchS11 had been opened, the brush would continue around the timer until itlanded at S11 and the searching switch SS opens so that the circuitthrough the shaded pole motor would have to pass through the printedcircuit board. At this time, since the switch S11 is open, the currentflow to the shaded pole motor will be interrupted and the rotor willretract to reverse the position of the switch 82. This, in turn, willallow current flow to the timer motor 36.

At this point it is well to consider the chart in FIG- URES 11A and Bwhich show a sample program available with this arrangement. It will benoted that the cycle selection switches (FIGURE 9) bear the numeralsindicating the interval at which the timer will be stopped in its rapidadvance. These intervals correspond to those intervals shown on FIGURE11 under the interval column and constitute the start of difiercntprograms. It will be noted that FIGURE 11 also shows, in the variouslabeled columns, the condition of the various switches operated by thetimer cams. These switches 1, 2, 3, 4 etc. appear in the lower portionof FIGURE 9 and control the washing machine apparatus or functionsassociated therewith as indicated on the diagram (FIGURE 9) as well ason the chart of FIGURE 11. The chart is easy to read. For example, inthe situation given above with the starting point at interval 11, thewash light (merely an indicator light) will be energized as will be themain motor through timer cam switch 3, the timer will be in circuit withthe closed switch 9 and switches 14 and 15 will also be closed. It willbe noted that the washing machine is provided with a pressure switch 126and, of course, at the start of this cycle, the empty contact will bemade. Hence, the timer motor 36 will not be energized until such time asthe pressure switch acts to make the full cont-act. However, with theenergization of switches 14 and 15, the solenoid actuating the hot watervalve will be open and the tub will start to fill. When the desiredlevel has been reached, the pressure switch will transfer to the fullcontact whereupon the timer motor will start operation. Thus, eventhough the tub may take four minutes to fill, only one interval has beenutilized for the fill operation and a full minute of time remains to beused after the filling before the next step of the stepping mechanism.

Reference to the chart will show that the timer could have been started,for example, at interval 13 which would result in a warm fill ratherthan a hot fill. If started at interval 11, however, as the timer stepsthrough interval 13, nothing will happen as regards filling since thepressure switch will have already transferred to the full contact and,hence, the mere fact that solenoid switch 18 is closed in interval 13will have no effect and no cold water will be taken into the tub. Thetimer will continue stepping until it reaches interval 21 at which timethe timer is turned off.

Before going on with other aspects of the present invention, it shouldbe noted that the cycle selection switches are coupled with a switch S40which will be open if all the selection switches are closed. Forexample, if the operator presses a latching type selection switch withan over-travel mechanism for establishing the momentary switch 120 andthen releases the switch which fails to latch in its open position, itwill be appreciated the motor would now be energized and could go onsearching for an open circuit not existing. Therefore, the switcharrangement is so designed that if all the cycle selection switches areclosed, the switch S40 will be open and this, as can be seen byreference to the chart in FIGURE 11, is an o position and, hence, noharm has been done and the machine will not continuously run searchingfor a condition which does not exist.

Reference was made earlier to the provision of multiple sequentialfunctions within a given interval. This arrangement will now beexplained. As was mentioned earlier, the gear disc 62 was provided witha plurality of circular face cams, the inner one of which operates thesearch switch SS. There are additional cams on the disc which operatewhat we term sub-interval switches. Now then, starting from the innercam, which operates the searching switch, the next cam track(progressing outwardly towards the periphery of the disc) will operatethe sub-interval switch D through the follower 128 cooperating withswitch labeled SD. The next cam track (progressing outwardly) operatesswitches SC and SE while the outermost cam track operates thesub-interval switches SA and SB. Now then, in FIGURE 10, there is showna chart of the sequence of operation of the subinterval switches. Therectangle in which the labeled rectangles appear represents, from leftto right, one interval as a matter of time and thus progressing from thelefthand margin, it will be noted that shortly after the start of aninterval, switch SA is made and remains closed for approximately /3 of acycle. Switch SA is thereupon opened and switch SB closes. At this time,switch SE also closes. SB remains closed for approximately 6 of a cycleand then opens, followed shortly by the closure of SC. SD closes shortlybefore the opening of SB and SD remains closed into the next interval asindicated by the small portion on the lefthand margin.

The sub-interval switches are included in the main timer circuit asindicated in FIGURE 9 and consideration of FIGURE 9 in combination withthe chart of FIGURE 11 will now demonstrate the novel functions possiblethrough such an arrangement. Refer, for example, to the operationsachieved at interval 17. Here, it will be noted, the same interval isused both for a rinse and for draining. Under former practice, this wasobviously incompatible since the drain pump would have to be energizedat the same time it was desired to fill the tub. However, an analysiswill show the practicality of the present arrangement. At interval 17the pump solenoid switch 8 is closed but it cannot operate the pumpuntil SC also closes. Hence, the pump cannot operate until the lastthird of the interval. Now then, the timer motor 36 is connected to thepower supply through the level switch and cam switch 9 which means thatupon the timer dropping into interval 17, the timer motor will turn offand will stay off until the tub has been filled. This has the effect ofstretching the interval to one long enough to allow the tub to fillregardless of the time required. It is obvious that the drainingoperation which, as explained before, can only occur during the latterthird of the interval, would not be very effective if the tub weresimultaneously undertaking to fill. Therefore, the fill is controlledthrough timer switch 13 which is in series with switch SA. Also closedat this time are the hot and cold solenoids 15 and 18. However, to fillthe tub after the timer drops into this interval, the circuit passesthrough the pressure switch and switch SA and the timer switch 13 to thesolenoids and causes filling which will continue with the timer total-1y at rest until the pressure switch trips to close the full contact andthis will then reenergize the timer. The timer having been re-energized,the sub-interval switching resumes operation and, before long, theswitch SA will open and no more filling can occur. When subintervalswitch SC closes in series with timer switch 8,

the pump will go into operation and start pumping down the contents ofthe tub. Obviously this would affect the pressure switch and would turnoff the timer motor with the result that the timer could not get out ofthis interval. This is accommodated by sub-interval switch SE which isin circuit with the timer 36 shunting the timer line switch 10.Obviously the line switch 10 could not have been closed during all thisoperation since a complete fill for the rinse purposes would not havebeen accomplished. It will be apparent, therefore, that the use of thesub-interval switching has accomplished within one interval, thefunctions which would normally require at least two intervals.Furthermore, due to the arrangement of the sub-interval switching, agreater period of time has been spent in the interval than the actualtheoretical duration of the interval. Thus, the fill alone could takefour or five minutes and there is still time within this interval toeffect the draining operation. Another advantage in this system is thatwhere the function desired requires less time than a complete interval,the complete interval need not be devoted to accomplishment of thefunction. Thus, the draining can be accomplished within about /3 of theinterval.

When the timer advances to step 18, this function is again repeated. Ingoing into interval 19, the pump is connected across the line by closureof switch 7 and the washer continues to pump down until sub-intervalswitch SD closes in series with timer switch 12 to energize the spin. Itwill be noted that interval SD extends into the subsequent interval andthis is to insure against the spin solenoid and the associatedtransmission being de-energized and re-energized between intervals.

The multiple functions thus afforded by sub-interval switching are muchthe same in the other intervals where the sub-interval switches are cutinto the circuit except that in interval 36, for example, during whichthe drain pumps are working constantly, there is a spray duringsubinterval B. Thus, in the first portion of the interval, the pumppulls down the water level so that the pressure switch will trip over tothe empty contact and when SB is made the circuit through the closedtimer switch 18 will be made to energize the cold solenoid and give acold spray. With the provision of the pressure switch, the sub-intervalswitch SB is not effective unless the pressure switch is in the emptyposition and either or both of the water solenoids 15 and 18 are closed.

One further feature afforded by the present arrangement should now bepointed out. As mentioned above, the cycle selection switch 56-8 ineffect, provides two stopping points, reference to the chart willdemonstrate the purposes of the two starting points. When this switch isfirst actuated, the tub gets a hot fill and agitation for the interval(6) period and then in interval 7, the machine turn off. This permitsthe clothes to be soaked the machine may be loaded and the 86-8 actuatedand the housewife may then leave the scene with the knowledge that themachine will turn off and allow the clothes to soak. When she pressesthe same button again, it will advance to interval 8 and then go intothe timing speed to the off position at interval 21. It will be notedthat one additional cycle selection switch has this feature. This isswitch S4244 where when the blanket button is first depressed, a warmfill will be obtained and the blanket may be soaked. Depressing thebutton again will start a timed soaking operation as indicated inintervals 44 through 49 whereupon the machine will go into the drain andrinse operation etc. finally turning 0E at interval 55. One switch,therefore, selects a sequence as it is operated sequentially. S6-8 whenfirst actuated must stop at interval 6 and when again actuated will stopat interval 8. The added versatility in programming at virtually no costis readily apparent.

The present invention constitutes an improvement over Thornbery et al.application Serial No. 799,781 insofar as the timer motor and the shadedpole motor use a common drive mechanism to step the timer. The driveincludes an improved stepping mechanism preventing overstepping asexplained more fully above. This invention also includes thesub-interval switching which, as explained above, greatly adds to theversatility of the machine. Heretofore, it was necessary to devote anentire interval to accomplishing a given function even though thefunction did not require the entire interval. By utilizing sub-intervalswitching, multiple functions can be performed within a given interval.A further feature is to be noted in connection with the sub-intervalswitching. It is possible with this system, to combine the betterfeatures of the stepping or interval timer and the creep type timer, thesub-interval switching arrangement being essentially a creep type timer.In the customary interval timer, a plurality of circuits aretheoretically made simultaneously upon the timer being stepped. Inpractice, however, there are manufacturing tolerances and there will besome slight spread in the switch closing and, with certain circuits, itis possible to have a momentary short circuit as a result of improperoperation of the switches. This is true in a switch which passes allmanufacturing inspection since it is a result of a very slight variationstill within manufacturing tolerances. With the present arrangement,however, it is possible to close a circuit prior to the normal intervalfor the closure and upon stepping to then transfer the control from thesubinterval switch to the main timer. This will insure the propersequencing and, as can be seen, frees the designer from the strictparameters laid down by the usual stepping arrangement. Now the designeris able to sequence a circuit independently of the interval timer and tolater transfer control of the circuit back to the interval timer.

Although but one embodiment of the present invention has beenillustrated and described, it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

We claim:

1. In a washing machine, an interval timer having a timer motor, a cambank driven by the timer motor in a step-by-step manner with the cambank operating interval switches according to a prescribed sequence, anda creep timer including a plurality of sub-interval switches sequencedonce for each interval of the prescribed sequence, said sub-intervalswitches being connected in circuit with certain of the intervalswitches to modify circuits controlled by the interval switches inaccordance with the operation of the sub-interval switches, and a 10switch responsive to a desired water level in the washing machine,including a circuit connecting the timer motor and the water levelswitch, and a sub-interval switch operative to shunt the level switchand connect the timer motor to a circuit, said sub-interval switch beingoperative at a predetermined interval in the prescribed sequence to makeenergization of the timer motor dependent upon the level switchindicating the desired level in the machine.

2. A washing machine according to claim 1 including a pump for drainingthe machine, a sub-intervalswitch connecting the pump to a circuit toempty the machine, the timer motor sub-interval switch and the pumpsubinterval switch both being closed during a portion of the time thatthe timer motor sub-interval switch is closed.

3. A washing machine according to claim 2 including a water supplymeans, a sub-interval switch in circuit with the water supply means andthe level switch whereby to effect filling the machine in saidpredetermined interval, the water supply means sub-interval switch beingclosed in the first portion of the interval, and the pump and motorsub-interval switches being closed in a later portion of the interval.

4. A washing machine according to claim 3 wherein one of said intervalswitches is in series with the pump sub-interval switch to control theintervals in which the pump sub-interval switch will be eifective.

5. An interval timer including a cam bank driven by a timer motor in astep-by-step manner with the cam bank operating interval switchesaccording to a prescribed sequence, a creep timer including a pluralityof sub-interval switches sequenced once for each interval of theinterval timer, said sub-interval switches being con nected in circuitwith certain of the interval switches to modify circuits controlled bythe interval switches in accordance with the operation of thesub-interval switches, one of said sub-interval switches being connectedin circuit with the timer motor, and a circuit in parallel with thetimer motor sub-interval switch and including a water level switchresponsive to a desired condition, whereby to shunt the sub-intervalswitch when the desired condition obtains.

References Cited in the file of this patent UNITED STATES PATENTS2,302,923 Zimarik Nov. 24, 1942 2,391,718 Lindemann Dec. 25, 19452,458,683 Cowherd et a1. Jan. 11, 1949 2,788,850 Leuenberger Apr. 16,1957

